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(ModeL) A. G. HOLGOMBE.

ELECTRIC ARC LAMP.

No. 329,166. Patented Oct. 27, 1885.

My F J A @EG [rzwmior UNITED STATES PATENT CFFICE.

ALFRED G. I-IOLCOMBE, OF NEYV YORK, N. Y., ASSIGNOR TO THE EQUITABLE ELECTRIC COMPANY, OF SAME PLACE.

ELECTRiC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 329,166, dated October 2 7, 1885.

Application filed December 15, 1882. Serial No. 79,3 1]. (ModeL) To all whom it may concern.-

Be it known that l, ALFRED G. HoLcoMBE, of New York, county and State of New York, have invented certain new and useful Improvements in Electric-Are Lamps, of which the following is a specification.

This invention relates to certain improvements in the electric-arc lamps patented March 21, 1882, and numbered 255,171, and has for its object to more perfectly control the action of the are forming and regulating mechanism by the addition thereto of a simple device, whereby the armature may be set in any part of the magnetic field of the poles of the act- 1 uating-magnets, and also be governed in its movement so as to regulate the distance that the upper carbon is raised to form the are. In the accompanying drawings,forming part of this specification, Figure 1 is a side elevation of the lamp, partly in section. Fig. 2 is a plan view of the upper part, partly in section. Fig. 3 is a central sectional view of the upper part on an enlarged scale, to more clearly show my improvements; and Fig. 4 is 2 a perspective view of the clutch and its coir trolling-lever and stops.

The lamp in its general construction is similar to that shown in the before-mentioned Letters Patent, viz: a coarse-wire electro-mag- 0 net, a a, in the arc-circuit, a fine-wire electromagnet, b b, in a branch circuit, one end of the cores of the two magnets being secured to the frame 0 of the upper part of the lamp, and their other ends connected together in pairs 5 by means of the curved pole-pieces (Z (l. The armature e is carried on one end of the lever f, formed, as shown, with a central opening,

through which the upper-carbon rod, 9, freely passes,arearwardly-extending arm, f,and two 0 lateral arms, ff, as the axis upon which the lever turns on two pointed screws, f 3 f passing through the frame e,and entering holes in the ends of the arms for this purpose. The rod 9 is gripped by the clutch h, havinga tail- 5 piece, h, by which it is supported near the ring in the bracket f of the lever, and this clutch is tilted to free the rod 9 when the armature end of the lever rises by means of the adj ustable set-screw, t, fitted in the end of the arm f of the lever, so that its point comes in con- [act with the extreme end of the tail-piece h of the clutch h.

So far this lamp is like that described in the patent referred to above, with the exception that the fulcrum on which the lever turns is placed farther from its armature end and nearer to the edge in the bracket f which supports the ring-clutch h. This is an important change, as the magnets have more power in lifting the rod 9 and its carbon j away from the lower carbon, 70, due to a greater movement of the armature 6 over the poles of the magnets, thus providing a more delicate action for such raising of the carbon.

Now, it will be observed that when the rod g is raised by the downward movement of the armature 0, due to the excess of current passing through the magnet a over that passing through the magnet I) when the lamp is first placed in circuit, the tail-piece h of the clutch moves away from the set-screw 'i, but gradually approaches thereto as the armature is moved upward over the poles of the magnets, due to a greater proportion of the current passing through the magnet Z), on account of the lengthening of the arc, until the tail-piece h touches the set-screw 1', thereby tilting the clutch h to allow the rod 5/ and carbon j to slide down to bringthe arc to itsnormal length and resistance. This action of the regulating 8o device is as near perfect as possible to maintain a constant are when once formed; but I experienced great difficulty in so adjusting the armature in relation to the consequent points of magnetism in the curved poles of the magnets, as such points vary in different lamps from various causes-such as non-uniformity of the iron forming the cores and pole-pieces of the lamp and of the wires surrounding them and also said consequent point-s vary when currents of different strength are used, that I found it necessary to make this class of lamps perfect to devise a means by which the armature 6 could be readily set to move over any part of the curved poles d and be kept within a certain range of movement to insure the proper action of the devicesin forming and maintaining the are. This adjustment and control of the movement of the armature and its lever I accomplish by means of the simple roe III device forming the subject of this invention, which consists of a set-screw, Z, passing upwardly through a bracket, Z, forming part of the arm f of the lever, said set-screw Z being directly opposite the set-screw i, so that the extreme end of the tail-piece h of the clutch it plays between their ends. The set-screwZ acts as a stop to govern the downward movement of the armature e and consequent upward movement of the rod g, thus also providing a means for regulating the length of the are formed between the carbon rods, be cause the are through which the set-screw Z moves is greater than that through which the point f moves, (the fulcrum of the lever f being a common center to both arcs,) and as the tail-piece h of the clutch h moves vertically with the point f" after the clutch has gripped the rod the point of the screw Z eventually comes in contact with this tailpiece It and prevents any farther downward movement of the armature e. The set-screw 6 determines the point at which the rod 9 is released when the armature moves in an opposite direction-namely, upwardly-as before described, by which it is evident the armature 6 may be caused to move over any part of the poles (Z (Z, and the range of its movement controlled to a nicety to form and maintain any length of are desired by simply adjusting the set-screws Z and The set-screw Z may be dispensed with if it is desired to have the clutch open always at a determined position of the lever. Such omission will not interfere with the proper func tion of the set-screwZ in regulating the length Any other form of adjustable conof the arc.

tact-piece may be substituted for the setscrew Z.

Having now described my invention, what I claim, and desire to secure byLetters Patent, 1s

1. In an electric-arc lamp, a rocking lever and actuating electro-magnet, in combination with a carbon-holding rod, a clutch, and two set-screws carried by the lever, whereby the working position of the lever and its range of motion are governed, substantially as and for the purpose set forth.

2. In an electric-arc lamp, in combination, the lever f f f Z, clutch h h, rod and setscrews '6 and Z, substantially as and for the purpose set forth.

3. In an electric-arc lamp, as a means for determining the length of the arc, the combination, with a carbon holding rod and a rocking lever, of a clutch provided with a tail piece and carried by thelever near its fulcrum, and a set-screw passing upwardly through the lever at its end, so as to come in contact with the under side of the tail-piece of the clutch when the clutch and carbon-holding rod have been lifted the desired distance by the lever to form the are, thereby preventing farther movement of the rocking lever in the direction to lift the clutch and carbon-holding rod, substantially as set forth.

In witness whereof I have hereunto set my hand, at New York, county and State of New York, this 14th day of December, A. D. 1882.

ALFRED G. HOLCOMBE.

Witnesses:

H. D. \VILLIAMS, ALFRED SHEDLOCK. 

